It has long been believed in evolution that whales and
hippos are related, but this has only been confirmed about 20 years ago. A few
days ago there has been another update to this evolutionary story. Scientists
have discovered a new missing link between the hippo and the whale. Starting in
1994 there have been expeditions led by Meave Leakey in Kenya looking for this
missing link. Leakey found the first tooth in 1994, and then returned to Kenya
in 2007. The teeth belong to an extinct species of mammals called the
anthracothere, ancestor of whales, hippos, cows, pigs and goats. It is believed
that the ancestor of the hippo swam the distance from Asia and was the first of
their kind to arrive in Africa around 33 million years ago.
Recently a
new member of the anthracothere species has been found in Kenya. This creature
is a distant relative of the modern day hippo. This creature is being called
the Epirigenys lokonensis, meaning the
original hippo of Lokone, with Lokone being the region that they found the teeth.
The Epirigenys lokonensis was smaller than the modern hippo only being
about the size of a sheep and weighing less than 250 pounds. Meanwhile the
modern hippo weighs anywhere from 3,000 to 6,000 pounds.
This link was made
because of the shape of the teeth of the organism found. Many mammal teeth are
distinct from that of others, having evolved to the food sources that they use.
Hippos and Epirigenys lokonenis share a similar pattern on their teeth, they
both have a similar 3 pronged maple leaf pattern on the top. This shape is
unique to the hippo.
Before teeth were used
to look at their evolution people believed that the hippo and the whale shared
no common ancestors. People believed that they we closely related to the pig,
due to their similarities in shape. 200 years ago scientists misinterpreted the
shape of the teeth and still believed that the pig was the closest relative.
While teeth are helpful things to look at when trying to look at evolution,
they cannot be the only source. Teeth are the pieces that are preserved the
longest, during that time they are subject to change from their environment. At
this time despite teeth being the only remains found there is no denying it,
whales are the hippos closest relative.
-Madison Boone (Group A)
Very weird to think about the fact the the closest relative to the hippo is the whale. You would think that the hippo would be more closely related to a terrestrial animal. It's strange how evolution/competition has driven these marine mammals to come out of the water, adapt to life on land, just to return to the ocean. Good job and interesting topic!
ReplyDeleteErika Nevins
Very interesting that an old tooth can tell us so much! When scientists do hypothesize a link based on a tooth's shape, is there another method of verifying that or is it the only available evidence?
ReplyDelete-Meghan Harrington
This is very informative I didn't know that hippos and whales were even believed to be related. Do you know what was the first clue to show that they are related or was it always teeth? Do you think that technology not available 200 years ago helped identify these teeth more accurately? I'm curious as to what led to this evolution its very interesting.
ReplyDelete-Jazmin Granadeno
This is very informative I didn't know that hippos and whales were even believed to be related. Do you know what was the first clue to show that they are related or was it always teeth? Do you think that technology not available 200 years ago helped identify these teeth more accurately? I'm curious as to what led to this evolution its very interesting.
ReplyDelete-Jazmin Granadeno
I had no idea that people believed pigs were closely related with hippos. I guess I can see why, but I think it's great that we've found undeniable proof that hippos are in fact related to whales, and that whales are their closest relative. I'm always very interested and excited when new species are discovered, whether they are extant or extinct!
ReplyDelete~ Mitchel Logan
Very interesting read! Fascinating to think that so many seemingly unrelated species share a common ancestor, and that it can all be deduced from a single tooth! Great article.
ReplyDelete-Hilary Mello
Super interesting! I think I remember learning about something similar to this (regarding ancestors of whales) in my Evolutionary Biology course. I think its awesome how evolution works. Great post!
ReplyDelete-Amanda Okpoebo
I really enjoyed your post; we actually were recently talking about this in my evolution class! It really shows how such a small change in the evolutionary scheme of life can cause such a divergence in species. Super interesting.
ReplyDelete-Rebecca Quirie
You discussed how at first we thought hippos were related to pigs due to morphological similarities. Discoveries that debunk our understanding of things always make me wonder just how many things we have "wrong" in science that we work off of the assumption to be true. We didn't even fully understand what DNA was until recently. What will be the next thing that redefines how we classify organisms?
ReplyDelete-Patrick O'Loughlin